There is a Saab service bulletin that says don't go changing the gas pedal, as it almost never solves the problem. You hound look at the electrical connnection located under the battery tray that gets battery acid dropping on it. That should be checked to make sure it is clean. I had the same problem with p2135 coming up on my 07 Saab 2.0T but only in cold weather, generally 32F and lower. I would get a surging sensation and know it wouldn't take long for the check engine light to come on and the car go into limp mode. I recently put in a used throttle body I bought at a junk yard (with a six month warranty!) and that solved the problem. There is an electric motor in the throttle body which turns the flap and I suspect what happens is it gets tired